1. Field of the Invention
The present invention relates to the field of switched telephony, and in particular, to wireless digital subscriber services, such as asymmetric digital subscriber line (ADSL) services, that provide fixed broadband data access to remote locations.
2. Background of the Invention
As electronic communication by businesses and private individuals has increased, the demand on network service providers for high speed, i.e., broadband, data transmission has steadily grown. Originally, service providers attempted to meet such demand with narrow band analog modems over traditional circuit-switched communication networks. However, these networks unnecessarily consumed resources because they set aside direct lines for data transmission even when no voice or data was being transmitted. Thus, to utilize network resources more efficiently than the circuit-switched communication networks, service providers are increasingly turning to packet-switched communication and broadband data services.
Packet-switched communication utilizes network capacity only when transferring voice or data. Data is sliced into small packets of information that are transmitted when a circuit is available. Circuits are not dedicated to certain user applications, as a phone service would be in a circuit-switched network. Instead, circuits remain open and available to all on-line users whenever they have data packets to transmit. This allocation strategy keeps lines open and saves network resources until they are actually needed for communication.
To accomplish this packet-switched broadband data communication, traditional network service providers typically use one of the following deployment options: (1) ADSL service using wired landlines (wireline ADSL); (2) integrated fiber in the loop (IFITL); or (3) ISDN, X.25, and other similar deployment services. In the prior art, the network service providers that own these wired telephone lines prefer wireline ADSL to deliver packet-switched data communication in service areas highly concentrated with customers because existing wire lines can be used, making ADSL inexpensive relative to the customer revenue produced in concentrated areas. However, broadband data rates over wire line facilities are distance dependent and require digital carrier systems for support once the length of wire line facilities exceed three miles from the central office. In contrast, in less concentrated and remote areas (e.g., rural areas), the smaller number of potential customers typically does not offer enough revenue to outweigh the costs to install and maintain the system. In addition, the longer deployment distances require more engineering efforts and capital investment in the improvement of line qualification to achieve expected transmission efficiency and quality. Therefore, potential customers in many locations typically do not have access to wireline ADSL service.
IFITL deployment improves the efficiency and quality of transmission over greater distances as compared to the wireline ADSL. However, the cost of installing optical fiber lines is very high, such that the limited numbers of distant potential customers would rarely, if ever, justify the initial investment.
Thus, there remains a need for a supplemental service that extends existing packet-switch data networks to less populated and remote areas that currently have no access. The deployment technique should be economical to install and should not suffer from reduced transmission quality over long distances. Further, the deployment method should enable network service providers to furnish remote customers with data access, while still realizing a profit.